shell模拟进度条

#!/bin/bash
b=''
for ((i=0;$i<=100;i+=2))
do
  printf "progress: [%-50s] %d%%\r" $b $i
  sleep 0.1
  b=#$b
done
echo


[root@gfs1 cwm]# sh she_t.sh
progress: [##################################################] 100%